Vocational fleets are taking a more active role in trying to solve vehicle equipment issues that fall outside typical Class 8 over-the-road operations.

Electrical, hydraulic, and braking systems are becoming their major concerns. Fleet managers from Waste Management Inc, along with other vocational fleets and equipment vendors, are working through The Maintenance Council (TMC) of the American Trucking Associations to solve their particular problems in those three areas.

Vocational fleet owners find not a good deal of communication exists between body and chassis engineers. Though both build one truck, each group tends to use its own specific software system to design truck systems, making the melding of vocational truck chassis and bodies more difficult, said Emile Hoffman, director of field service support for Waste Management.

Hoffman's TMC study group is working with 12 equipment vendors, including truck makers Volvo, Freightliner, and Mack and refuse body builders Heil and McNeilus, to try to untangle electrical wiring issues by improving communications and standardizing wiring components.

Waste Management expressed even more concern about brakes. The company said heavy loads its vehicles carry in a stop-and-go environment are requiring brake jobs to be done every 60 to 70 days. Other problems include slack adjusters that go out of alignment rapidly and the relay between tag axles not being in sync.

Puget Sound Truck Lines of Seattle WA also reported its heavy-haul equipment for wood chips means relining its vocational truck brakes four times a year.

As for hydraulics, Waste Management's Don Beck is heading another study group looking for ways to to decrease life-cycle costs of vocational truck hydraulics. Fourteen manufacturers are involved. They are looking at issues such as hydraulic fluid contamination, filter position within hydraulic systems, and hydraulic hose ratings. The group's findings should be applicable to all vocational fleets, whether in the cement mixer, electric power, or auto hauling business, said Beck.